Image reading apparatus and image forming apparatus

ABSTRACT

An image reading apparatus includes an image scanning unit that is provided with a holding portion holding a flexible flat cable. The holding portion is protruded toward an upstream side in a sub scanning direction, and provided with a second wall part. The flexible flat cable that is extended from a connector is brought into contact with the second wall part. As for the flexible flat cable, a downward movement is regulated by a lower holding portion and an upward movement is regulated by an upper holding portion. Accordingly, the flexible flat cable does not rise.

CROSS REFERENCE OF RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/653,424, filed Jul. 18, 2017, which is a continuation of U.S.application Ser. No. 15/206,476, filed Jul. 11, 2016, which is acontinuation of U.S. application Ser. No. 14/311,586, filed Jun. 23,2014, now U.S. Pat. No. 9,420,142, which is based on Japanese PatentApplication No. 2013-130588, filed Jun. 21, 2013, and Japanese PatentApplication No. 2014-041893, filed Mar. 4, 2014, the disclosures of eachof which are incorporated herein by reference.

BACKGROUND OF THE INVENTION Field of the invention

The present invention relates to an image reading apparatus that readsan image from an original and an image forming apparatus that forms animage read from an original onto a recording medium. Description of therelated art

Conventionally, an image reading apparatus of a flat-bed type, and animage forming apparatus such as a copying machine, a facsimileapparatus, a digital multifunction machine, etc. each being providedwith such an image reading apparatus are known. Such a flat-bed typeimage reading apparatus is constructed such that an image scanning unitthat has a light source irradiating an original with a light and a closecontact type photoelectric conversion device such as a CIS (ContactImage Sensor) is arranged beneath a platen glass, and an original thatis being put on the platen glass is scanned by the image scanning unitthat is moved along the platen glass so as to read an image.

An example of the flat-bed type image reading apparatus is disclosed inJapanese Patent Application Laying-Open No. 2003-233138 [GO3B 27/50,HO4N 1/00, HO4N 1/04, HO4N 1/10, HO4N 1/107] laid-open on Aug. 22, 2003(Literature 1). In an image reading apparatus disclosed in thisLiterature 1, in order to prevent a dirt of a glass, a disconnection ofthe flexible flat cable and a malfunction by a flexible flat cable thatconnects a control board provided on a main body and an image scanningunit to each other being brought into contact with the glass, theflexible flat cable is arranged to be raised in a direction orthogonallyintersecting the platen glass.

However, it is impossible to prevent the flexible flat cable from movingup and down with the movement of the image scanning unit by only simplyarranging the flexible flat cable perpendicularly as in the imagereading apparatus disclosed in Literature 1, and therefore, there is anoccasion that the flexible flat cable is brought into with the glass.

SUMMARY OF THE INVENTION

The present invention is accomplished in view of such circumstances, anda primary object of the present invention is to provide an image readingapparatus and an image forming apparatus, capable of solving theabove-described problem.

In order to solve the above-described problem, an image readingapparatus of an aspect according to the present invention comprises: aflat-plate-like transparent plate on which an original is put; ascanning portion that is provided beneath the transparent plate and hasa light source that irradiates the original being put on the transparentplate with at least light; an image outputting portion that outputs animage signal according to the original based on a result that theoriginal is scanned by the scanning portion; and belt-like signal cablethat has one end connected to the scanning portion and another endconnected to a circuitry portion that receives at least the image signaloutput from the image outputting portion, wherein the signal cable isarranged such that a width direction of the signal cable intersects adirection along a main surface of the transparent plate, and thescanning portion is provided with an upper regulating portion thatregulates an upward movement of the signal cable.

In this aspect, the upper regulating portion may have a slant surfacethat is inclined downward as far from the one end of the signal cable.

Furthermore, in the above-described aspect, the scanning portion may befurther provided with a release preventing portion that prevents thesignal cable from releasing from the upper regulating portion.

Furthermore, in the above-described aspect, the scanning portion may beprovided with a lower regulating portion that regulates, at a positiondifferent from the upper regulating portion in a longitudinal directionof the signal cable, a downward movement of the signal cable.

Furthermore, in the above-described aspect, the scanning portion may beprovided with a connection portion where the scanning portion isconnected to the one end of the signal cable such that a width directionof the one end of the signal cable becomes the direction along the mainsurface of the transparent plate, and a shape holding portion that holdsthe signal cable such that the width direction of the signal cableextended from the connection portion is changed toward a directionintersecting the main surface of the transparent plate as far from theone end.

Furthermore, in the above-described aspect, the signal cable may bebrought into contact with the shape holding portion at a position lowerthan the connection portion of the scanning portion.

Furthermore, in the above-described aspect, the lower regulating portionmay be provided in contiguity with the shape holding portion.

Furthermore, in the above-described aspect, the shape holding portionmay be constructed to have a wall portion that is, in at least a part,opposite to the connection portion, and the signal cable extended fromthe connection portion is brought into contact with the wall portion.

Furthermore, in the above-described aspect, the wall portion may beconstructed such that a first part that is opposite to a part of theconnection portion is provided below the connection portion and a secondpart that is opposite to another part of the connection portion isextended above the first part.

Furthermore, an image reading apparatus of another aspect according tothe present invention comprises: a flat-plate-like transparent platethat puts an original thereon; a scanning portion where is providedbeneath the transparent plate and has a light source that irradiates theoriginal being put on the transparent plate with at least light; and abelt-like signal cable that has one end connected to the scanningportion and another end connected to a circuitry portion that receivesat least the image signal based on a result that the original is scannedby the scanning portion, wherein the signal cable is extended along awall portion where is extended in a moving direction of the scanningportion in a state that the one end is connected horizontally withrespect to a direction where the scanning portion is extended and israised vertically from the horizontal state, and the scanning portion isprovided with an upper regulating portion where regulates an upwardmovement of the signal cable within a section where the signal cable ischanged from the horizontal state to the vertical state.

Furthermore, an image forming apparatus of an aspect according to thepresent invention comprises: the image reading apparatus in theabove-described aspects; and an image forming portion where forms animage that is read by the image reading apparatus onto a recordingmedium.

The above described objects and other objects, features, aspects andadvantages of the present invention will become more apparent from thefollowing detailed description of the present invention when taken inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view showing entire structure of an image formingapparatus according to a first embodiment.

FIG. 2 is a plan view showing structure of an image reading apparatus ina state that an upper housing is removed.

FIG. 3 is a cross-sectional view at a line A-A′ shown in FIG. 2 of theimage reading apparatus in a state that the upper housing is attached.

FIG. 4 is a front cross-sectional view showing structure of an imagescanning unit.

FIG. 5 is a plan view showing structure of a rear end portion of theimage scanning unit.

FIG. 6 is a side view showing the structure of the rear end portion ofthe image scanning unit.

FIG. 7 is a plan view showing the structure of the rear end portion ofthe image scanning unit in a state that a flexible flat cable is notconnected thereto.

FIG. 8 is a side view showing the structure of the rear end portion ofthe image scanning unit in the state that the flexible flat cable is notconnected thereto.

FIG. 9 is a front cross-sectional view schematically showing holdingstructure of the flexible flat cable by a holding portion.

FIG. 10 is a plan cross-sectional view showing the structure of theimage reading apparatus at a time that the image scanning unit isarranged at an initial position.

FIG. 11 is a side view schematically showing the holding structure ofthe flexible flat cable by a lower holding portion and an upper holdingportion.

FIG. 12 is an enlarged side view of the upper holding portion.

FIG. 13 is a cross-sectional view at a line B-B′ shown in FIG. 12.

FIG. 14 is a perspective view showing the structure of the rear endportion of the image scanning unit in a state that the flexible flatcable is not connected thereto.

FIG. 15 is an enlarged cross-sectional view of another example of theupper holding portion.

FIG. 16 is a transparent view seeing through a side surface a part of animage reading apparatus utilized in an image forming apparatus accordingto a second embodiment.

FIG. 17 is a perspective view showing structure of an image readingportion in the second embodiment.

FIG. 18 is a plan view showing structure of an image reading apparatusin a state that an upper housing is removed in a third embodiment.

DETAILED DESCRIPTION OF NON-LIMITING EXAMPLE EMBODIMENTS

In the following, preferred embodiments according to the presentinvention will be described with referring to the drawings.

First Embodiment

FIG. 1 is a partially-cross-sectional view showing entire structure ofan image forming apparatus according to the first embodiment.

An image forming apparatus 1 according to the first embodiment comprisesan image reading apparatus 10 that reads an image from an original and amain body (an image forming portion) 20 that forms an image read by theimage reading apparatus 10 onto a recording paper that is a recordingmedium. In FIG. 1, a Z direction is a vertical direction, and a Z1direction shows an upward direction and a Z2 direction shows a downwarddirection. The image forming apparatus 1 is arranged, in a using state,on a floor in a manner that the image reading apparatus 10 is positionedabove the main body 20. Furthermore, in FIG. 1, a Y direction (onedirection in a horizontal direction) orthogonally intersecting avertical direction is called as a sub scanning direction, and a Y1direction is a downstream side of the sub scanning direction and a Y2 isan upstream side of the sub scanning direction. Furthermore, a directionorthogonally intersecting both of the Z direction and the Y direction(one direction in the horizontal direction orthogonally intersecting theY direction, that is, an X direction in FIG. 2) is called as a mainscanning direction, and one of the main scanning direction is renderedas the front (an X1 direction in FIG. 2, etc., that is, a front side)and the other of the main scanning direction is rendered as the rear (anX2 direction in FIG. 2, etc.). The structure of the image formingapparatus 1 viewed from the front is shown in FIG. 1.

The main body 20 is provided with a photoreceptor drum 21, anelectrostatic charger 22, an exposure device 23, a developing device 24,a transfer device 25, a fixing device 26, a paper feed tray 27, etc. Insuch a main body 20, an image is formed onto a recording paper asfollows:

First, a latent image is formed on a surface of the photoreceptor drum21 by exposing by the exposure device 23 the surface of thephotoreceptor drum 21 that is electrostatically charged by the charger22 according to an image that is read by the image reading apparatus 10.Next, the developing device 24 develops the latent image that is formedon the photoreceptor drum 21 by a toner. A toner image that is thusformed on the photoreceptor drum 21 is transferred onto a transfer beltthat is provided on the transfer device 25, and then, the toner image onthe transfer belt is transferred on a recording paper that is fed fromthe paper feed tray 27. The recording paper is heated by the fixingdevice 26, whereby the toner image that is formed onto the recordingpaper is melted and mixed while the toner image is pressure-contactedwith the recording paper. The recording paper after the toner image isfixed is discharged on a paper discharging tray 28 that is provided onthe main body 20.

The image reading apparatus 10 is arranged above the main body 20.Furthermore, above the image reading apparatus 10, an automatic documentfeeder 30 that functions as a platen cover is arranged.

Structure of the image reading apparatus 10 will be described with usingFIG. 2 and FIG. 3. The image reading apparatus 10 comprises a platenglass (transparent plate) 2, an image scanning unit (image readingportion) 3, a driving mechanism (driving portion) 4 that drives theimage scanning unit 3, and a control circuit (circuitry portion) 5 thatprocesses a signal that is output from the image scanning unit 3. Eachof the image scanning unit 3, the driving mechanism 4 and the controlcircuit 5 is accommodated within a housing 6 that forms a rectangularparallelepiped box. The housing 6 is constructed by an upper housing 6 aand a lower housing 6 b. FIG. 2 is a plan view of the image readingapparatus in a state that the upper housing 6 a is removed, and FIG. 3is a cross-sectional view at a line A-A′ of the image reading apparatusin a state that the upper housing 6 a is attached.

The platen glass 2 is constructed by a glass having a transparency, andis used as an original table for putting an original thereon. Such aplaten glass 2 is a rectangular plate larger than a maximum size of theoriginal, and is fit into a rectangular frame of the upper housing 6 a(see FIG. 3) such that the main surface thereof is extended in thehorizontal direction.

FIG. 4 is a front cross-sectional view showing structure of the imagescanning unit 3. The image scanning unit 3 has a pair of light sourceportions 31 for irradiating the original being put on the platen glass 2with lights, a lens array 32 that is arranged between the two lightsource portions 31, and a line sensor 33 that receives a light that isreflected by the original and passed through the lens array 32 so as tooutput an electric signal according to a light amount (hereinafter,called as “image signal”).

Each of the light source portions 31, the lens array 32 and the linesensor 33 is extended long in the main scanning direction (X directionin FIG. 2 and FIG. 3), and accommodated within a box-like housing 34that is also extended long in the main scanning direction and has a slitin an upper portion thereof. Such an image scanning unit 3 is fixed to abase 35 that is extended long in the main scanning direction. The lensarray 32 is constructed by a plurality of lenses that are arranged in asingle line in the main scanning direction. In addition, the line sensor33 is constructed by a plurality of photo-detectors that are arranged ina single line in the main scanning direction. The lenses of the lensarray 32 and the photo-detectors of the line sensor 33 correspond toeach other one-to-one, and it is constructed such that a light passingthrough the lens can be received by the photo-detector. By the imagescanning unit 3 having such structure, the original can be scanned inthe main scanning direction.

As shown in FIG. 2 and FIG. 3, there is provided with a guide rail 61that is extended in the sub scanning direction (Y direction) in thevicinity of a center in the main scanning direction on an inner bottomsurface of the lower housing 6 b. To the guide rail 61, a recess portionthat is formed on a bottom of the base 35 of the image scanning unit 3is engaged. The image scanning unit 3 is slidable along the guide rail61. That is, it is constructed such that a moving direction of the imagescanning unit 3 is regulated within the sub scanning direction by theguide rail 61.

Furthermore, a wall portion 62 that is extended in the sub scanningdirection is provided inside the housing 6. By the wall portion 62, amoving area 7 a for the image scanning unit 3 and an area 7 b forarranging the control circuit 5 are sectioned from each other.

The driving mechanism 4 includes a stepping motor 41, a plurality ofgears 42 that transmit a rotation force that is output by the steppingmotor 41, a driving pulley 43 that is driven by the stepping motor 41via the gears 42, a driven pulley 44, and an endless belt 45 that isstretched between the driving pulley 43 and the driven pulley 44 (FIG.2).

The stepping motor 41 is arranged in the vicinity of the center of themain scanning direction at an upstream side of the sub scanningdirection inside the housing 6. The driving pulley 43 is arranged at aposition slightly ahead of the stepping motor 41. The driven pulley 44is arranged at a position opposite to the driving pulley 43 at adownstream side of the sub scanning direction inside the housing 6,whereby the belt 45 is extended in the sub scanning direction to bestretched between the driving pulley 43 and the driven pulley 44. Thatis, the belt 45 and the guide rail 61 are arranged in parallel with eachother. Such a belt 45 is arranged at a position slightly ahead of theguide rail 61.

The base 35 of the image scanning unit 3 is connected to a part of thebelt 45. When the stepping motor 41 is rotated, the rotation force ofthe stepping motor 41 is transmitted to the driving pulley 43 via thegears 42, whereby the belt 45 is moved in an orbital manner between thedriving pulley 43 and the driven pulley 44. At this time, the imagescanning unit 3 is moved in the sub scanning direction together with thebelt 45.

If an original is put on the platen glass 2 and a reading startinstruction is applied by the user, the image scanning unit 3 that isarranged at a position at the upstream side of the sub scanningdirection inside the housing 6 (hereinafter, called as “initialposition”) is moved, in the sub scanning direction, toward a position atthe downstream side of the sub scanning direction inside the housing 6(hereinafter, called as “end position”) by the driving mechanism 4 at aconstant speed. During such a movement, by repeatedly scanning theoriginal by the line sensor of the original scanning unit 3, an entiresurface of the original contacting with the platen glass 2 can bescanned.

The control circuit 5 is arranged in the rear side area 7 b defined bythe wall portion 62 inside the housing 6. The control circuit 5 includesa driving circuit for driving the stepping motor 41, a signal processingcircuit for processing the image signal that is output from the imagescanning unit 3, and an electric power source circuit. Such a drivingcircuit 5 and the stepping motor 41 are connected to each other by adrive signal transmitting cable 51. Furthermore, the control circuit 5and the image scanning unit 3 are connected to each other by a belt-likeflexible flat cable (signal cable) 52 for transmitting the image signal.

FIG. 5 is a plan view showing structure of a rear end portion of theimage scanning unit 3 and FIG. 6 is a side view thereof. Furthermore,FIG. 7 is a plan view showing the structure of the rear end portion ofthe image scanning unit 3 in a state that the flexible flat cable is notconnected thereto, and FIG. 8 is a side view thereof, and FIG. 14 is aperspective view thereof.

As understood by referring to FIG. 5 to FIG. 8 and FIG. 14, there isprovided with a connector (connection portion) 34 a for outputting theimage signal in the vicinity of the rear end portion of the imagescanning unit 3. To such a connector 34 a, one end of the flexible flatcable 52 is connected. The connector 34 a has a long shape in the mainscanning direction, i.e., in a direction along the main surface of theplaten glass 2, and to the connector 34 a, the one end of the flexibleflat cable 52 is connected such that the one end becomes long from sideto side.

The base 35 of the image scanning unit 3 is provided with a holdingportion (shape holding portion) 351 that holds the flexible flat cable52. The holding portion 351 is provided to be protruded toward theupstream side of the sub scanning direction from a position beneath theconnector 34 a (Y2 direction in FIG. 5 and FIG. 7). Such a holdingportion 351 is formed in a trapezoid shape approximately when viewedfrom the top. A side of a long side of the trapezoid is a base end sidethat is connected to the base 35, and a side of a short side is a tipend side that is protruded from the base 35.

The holding portion 351 comprises a bottom plate portion 353 and a wallportion 352 (see FIG. 5, FIG. 7, FIG. 8 and FIG. 14). The bottom plateportion 353 is in a trapezoid shape approximately as described above.The wall portion 352 is provided to be raised upward along an outer edgeof the bottom plate portion 353. Such a wall portion 352 is constructedby successive three parts of a first wall part (a first part) 352 a, asecond wall part (a second part) 352 b and a third wall part 352 c.

The first wall part 352 a is provided on a rear oblique side of theaforementioned trapezoid, the second wall part 352 b is provided on ashort side, and the third wall part 352 c is provided on a front obliqueside. It is constructed such that the first wall part 352 a that isprovided on the rear oblique side is lower than the second wall part 352b and the third wall part 352 c, and the third wall part 352 c that isprovided on the front oblique side is higher than the first wall part352 a and the second wall part 352 b.

Furthermore, the third wall part 352 c that is provided on the frontoblique side has a height that is constant from a front end (a portionadjacent a hiatus portion 36 a (described later)) to a middle portion,and linearly inclined to be lower as going to the rear (X2 direction inFIG. 5 to FIG. 8) from the middle portion to the rear end (connectionportion with the second wall part 352 b). The second wall part 352 bthat is provided on the short side is linearly inclined to be lower asgoing to the rear over the whole from the front end (connection portionwith the third wall part 352 c) to the rear end (connection portion withthe first wall part 352 a).

Furthermore, a height of the second wall part 352 b at the front end isidentical to a height of the third wall part 352 c at the rear end. Thefirst wall part 352 a that is provided on the rear oblique side has aconstant height over the whole from the front end (connection portionwith the second wall part 352 b) to the rear end, and the height isidentical to a height of the second wall part 352 b at the rear end.That is, the first wall part 352 a, the second wall part 352 b and thethird wall part 352 c are connected to each other such that the heightis successively changed.

Each of the first wall part 352 a and the second wall part 352 b isopposite to the connector 34 a. Especially, the second wall part 352 bis provided in parallel with the connector 34 a and thus faces theconnector 34 a. That is, the front side portion of the connector 34 a isopposite to the second wall part 352 b, and the rear side portion of theconnector 34 a is opposite to the first wall part 352 a. Furthermore, aposition at an upper end of the first wall part 352 a is lower than aposition that the connector 34 a is provided. Thus, the whole of thefirst wall part 352 a having a lower height is opposite to the rear sideportion of the connector 34 a, and in the second wall part 352 b facingthe front side portion of the connector 34 a, the height is lowered asgoing toward the rear, and accordingly, at a time that an operatorconnects the flexible flat cable 52 to the connector 34 a, it isprevented that wall portion 352 from interfering the work, andtherefore, it is possible to perform assembling efficiently.

As shown in FIG. 5 and FIG. 6, the flexible flat cable 52 that isconnected to the connector 34 a at the one end thereof is extendedtoward the upstream side of the sub scanning direction, and a furtherahead portion thereof is turned down in an opposite direction (thedownstream side of the sub scanning direction. Y1 direction in FIG. 5)while being twisted. This turned down portion is formed by turning-downthe flexible flat cable 52 to be curved. That is, the flexible flatcable 52 is changed in its width direction long from side to side fromthe horizontal direction to the perpendicular (vertical) direction asfar from the one end. By forming such a turned down portion, theflexible flat cable 52 is not formed with a fold that is to be formedwhen the flexible flat cable 52 is bended, and thus, a disconnection canbe prevented from occurring. Such the turned down portion of theflexible flat cable 52 is stored in an interior of the holding portion351, thereby to be brought into contact with the second wall part 352 b.

Holding structure for the flexible flat cable 52 in the holding portion351 will be described in more detail. FIG. 9 is a front cross-sectionalview schematically showing the holding structure for the flexible flatcable 52 in the holding portion 351.

As shown in FIG. 9, the flexible flat cable 52 is extended toward theupstream side of the sub scanning direction from the connector 34 awhile being inclined downward, and turned down at a corner portion thatthe bottom plate portion 353 of the holding portion 351 and the secondwall part 352 b are connected to each other, that is, in the vicinity ofthe lower end of the second wall part 352 b to be brought into with thesecond wall part 352 b.

Since a contacting position P1 of the flexible flat cable 52 in thesecond wall part 352 b is a position lower than the connector 34 a, adistance D1 from the connector 34 a to the contacting position P1 islonger than a shortest distance from the connector 34 a to the secondwall part 352 b, i.e., a distance DO from the connector 34 a to thesecond wall part 352 b in the horizontal direction. That is, the lengthD1 of a portion 52 a (hereinafter, called as “connection end portion”)from the connection place that the flexible flat cable 52 is connectedto the connector 34 a to the turned down place is longer than theshortest distance DO from the connector 34 a to the second wall part 352b.

Accordingly, if the connection end portion 52 a that is arranged at aposition lower than a position PO that the second wall part 352 bapproaches the connector 34 a most is to be moved upward beyond theportion P0, it is necessary to deform the connection end portion 52 a;however, since flexible flat cable 52 has a flexibility as well as anelasticity, even if the connection end portion 52 a is to be deformed, aforce that restores such a deformation occurs by the elasticity, andtherefore, the deformation is inhibited.

Furthermore, the connection end portion 52 a is pushed against thesecond wall part 352 b by such a restoring force, and therefore, theconnection end portion 52 a receives a drag force at a side of theconnector 34 a from the second wall part 352 b. Accordingly, a staticfriction force occurs between the connection end portion 52 a and thesecond wall part 352 b.

Therefore, the connection end portion 52 a is engaged with the secondwall part 352 b, and thus, the rise of the connection end portion 52 ais prevented, whereby the connection end portion 52 a can be surely heldby the holding portion 351.

As described above, the front side portion of the connector 34 a facesthe second wall part 352 b. Furthermore, the second wall part 352 b isconstructed such that the height thereof comes higher as going forward(FIG. 6, FIG. 8 and FIG. 14). Therefore, the front side portion of theconnector 34 a faces the second wall part 352 b that the height issecured, and the connection end portion 52 a of the flexible flat cable52 that is extended from the connector 34 a is surely brought intocontact with the second wall part 352 b. In addition, because the heightof the second wall part 352 b is secured, the connection end portion 52a that is engaged with the second wall part 352 b is prevented fromreleasing from the second wall part 352 b. Furthermore, since the turneddown portion of the flexible flat cable 52 is brought into contact withthe second wall part 352 b as described above, the connection portion tothe connector 34 a of the flexible flat cable 52 is prevented from beingfallen out of the connector 34 a.

In addition, the structure that the connector 34 a and the second wallpart 352 b confront to each other is adopted, but not limited to suchthe structure, and the connector 34 a and the second wall part 352 b maynot be provided in parallel with each other as far as the connector 34 aand the second wall part 352 b are opposite to each other. If theconnector 34 a and the second wall part 352 b are opposite to eachother, since it is possible, as similar to the above, to engage theflexible flat cable 52 that is extended from the connector 34 a with thesecond wall part 352 b, the connection end portion 52 a of the flexibleflat cable 52 can be held.

The flexible flat cable 52 that is thus turned down at the holdingportion 351 is extended toward the downstream side of the sub scanningdirection while being inclined forward (X1 direction in FIG. 5) alongthe third wall part 352 c by being applied with the twist at the turneddown portion (see FIG. 5). A straight portion 354 a that is extendedforward (main scanning direction) is provided at a front end of thethird wall part 352 c, and there is provided with a hiatus portion 36 athat is deeply incised from an upper side in the vertical directionfurther forward the straight portion 354 a (see FIG. 8). The straightportion 354 a is communicated with a wall portion 37 that is extended inthe main scanning direction via such the hiatus portion 36 a.Furthermore, at the downstream side of the sub scanning direction fromthe straight portion 354 a, there is formed with a gap for arranging theflexible flat cable 52, and beneath the gap, a bottom plate portion 354b that follows to the bottom plate portion 353 of the holding portion351 (see FIG. 7) is provided.

A further ahead portion of the turned down of the flexible flat cable 52is inclined such that a plane portion turns to an oblique upper by beingturned down while being twisted (see FIG. 5 and FIG. 6). An even furtherahead portion thereof is twisted in a reverse direction such that theplane portion that has turned the oblique upper comes to standsubstantively vertically, and inserted into the hiatus portion 36 a tobe supported. The hiatus portion 36 a has a recess that an upper portionis opened, and a lower holding portion 36 that holds the flexible flatcable 52 from the bottom is constructed by the straight portion 354 aconstituting the hiatus portion 36 a, the bottom plate portion 354 b andthe rear end portion of the wall portion 37 (see FIG. 6, FIG. 7 and FIG.14). That is, as for the flexible flat cable 52, a downward movement isregulated by the bottom plate portion 354 b. In this point, it ispossible to say that the lower holding portion 36 or the bottom plateportion 354 b is a lower regulating portion.

There is provided with an upper holding portion 38 that holds theflexible flat cable 52 from the top further forward from the lowerholding portion 36 (see FIG. 5 to FIG. 7 and FIG. 14). The upper holdingportion 38 is provided on an upper end of the wall portion 37, and formsa hook-like shape. Such an upper holding portion 38 is engaged with theupper end of the flexible flat cable 52, whereby the flexible flat cable52 can be held by the upper holding portion 38 from the top. That is, asfor the flexible flat cable 52, an upward movement is regulated by theupper holding portion 38. In this point, it is possible to say that theupper holding portion 38 is an upper regulating portion.

As described above, the flexible flat cable 52 is held at three placesby the holding portion 351, the lower holding portion 36 and the upperholding portion 38.

The lower holding portion 36 as described above is provided at aposition that is separated from the rear end of the connector 34 a by adistance of approximately 2 times the width of the flexible flat cable52. Furthermore, the upper holding portion 38 is provided at a positionthat is separated from the rear end of the connector 34 a by a distanceof approximately 2.5 times the width of the flexible flat cable 52 (seeFIG. 5).

If the upper holding portion 38 is too far from the connector 34 a,there is an apprehension that a rise occurs due to a flexion of theflexible flat cable 52 between the connector 34 a and the upper holdingportion 38. Furthermore, if the lower holding portion 36 is too far fromthe connector 34 a, similarly, there is an apprehension that a rise ofthe flexible flat cable 52 occurs.

On the other hand, if the upper holding portion 38 is too close to theconnector 34 a, there is an apprehension that a wiring operation of theflexible flat cable 52 becomes difficult because it is necessary to formthe above-described twist and turned-down between the connector 34 a andthe upper holding portion 38. If the lower holding portion 36 is tooclose to the connector 34 a, similarly, there is an apprehension that awiring operation of the flexible flat cable 52 becomes difficult.Therefore, by providing the lower holding portion 36 and the upperholding portion 38 at the above-described positions, it becomes possibleto make a wiring operation of the flexible flat cable 52 easy whilepreventing the rise thereof.

The flexible flat cable 52 is extended toward the upstream side of thesub scanning direction beyond a place that the flexible flat cable isheld by the upper holding portion 38, and further ahead, horizontallyturned down in a U-letter shape, and then, turned behind the imagescanning unit 3 passing through an outer side of the holding portion351, and extended to the downstream side of the sub scanning directionalong the wall portion 62 (see FIG. 2). A hiatus portion beingvertically cut is formed on the middle portion of the wall portion 62,and the flexible flat cable 52 is brought into the area 7 b that thecontrol circuit 5 is arranged behind the wall portion 62 passing throughthe hiatus portion. Inside the area 7 b, the flexible flat cable 52 istwisted horizontally from a state that the flexible flat cable 52 standsvertically, and in turn, connected to the control circuit 5.

As shown in FIG. 2, there is provided, in an end portion of the upstreamside of the sub scanning direction inside the housing 6, with anarranging area 7 c that the stepping motor 41, the gears 42 and thedriving pulley 43 are arranged therein. A position at the downstreamside of the sub scanning direction from the arranging area 7 c is theinitial position of the image scanning unit 3.

FIG. 10 is a plan view showing structure of the image reading apparatus10 at a time that the image scanning unit 3 is arranged at the initialposition. An initial position detecting sensor 46 including aphoto-interrupter is provided in the arranging area 7 c. On the otherhand, a detection piece 39 is provided protuberantly toward the upstreamside of the sub scanning direction at a position in front of the upperholding portion 38 on the wall portion 37 of the image scanning unit 3(see FIG. 5 to FIG. 8). If the image scanning unit 3 is positioned atthe initial position, the detection piece 39 is detected by the initialposition detecting sensor 46 (see FIG. 10). Thus, it is detected thatthe image scanning unit 3 is at the initial position.

In FIG. 2, a state that the image scanning unit 3 is moved from theinitial position to the downstream side of the sub scanning direction isshown. As shown in FIG. 2, the moving area 7 a of the image scanningunit 3 is protruded toward the upstream side of the sub scanningdirection behind the area 7 c that the stepping motor 41, etc. arearranged. This portion is an area 7 d for accommodating the holdingportion 351 that is protruded toward the upstream side of the subscanning direction from the image scanning unit 3. That is, when theimage scanning unit 3 is positioned at the initial position, the holdingportion 351 is accommodated in the area 7 d (see FIG. 10). Thus, it isconstructed such that the holding portion 351 does not interfere withother portions at a time that the image scanning unit 3 is at theinitial position.

Since the flexible flat cable 52 is held from the top by the upperholding portion 38 by constructing as described above, the movement ofthe flexible flat cable 52 is prohibited by the upper holding portion 38even if the flexible flat cable 52 is going to move upward. The rise ofthe flexible flat cable 52 is thus prevented by the upper holdingportion 38, and therefore, the dirt of the platen glass 2, thedisconnection of the flexible flat cable 52 and the malfunction all dueto the contact of the flexible flat cable 52 with the platen glass 2 areprevented.

Furthermore, since it is constructed such that the lower holding portion36 is provided at a position close to the connector 34 a in comparisonwith the upper holding portion 38, and the flexible flat cable 52 isheld from the bottom by the lower holding portion 36 and the flexibleflat cable 52 is held from the top by the upper holding portion 38, therise of the flexible flat cable 52 is prevented still more.

FIG. 11 is a side view schematically showing holding structure of theflexible flat cable 52. In FIG. 11, hatching by slant lines is appliedto the flexible flat cable 52. As shown in FIG. 11, the flexible flatcable 52 is held by the lower holding portion 36 and the upper holdingportion 38 at different positions in the horizontal direction, i.e., alongitudinal direction of the flexible flat cable 52.

At a place that the flexible flat cable 52 is held by the lower holdingportion 36, and an upward movement is not regulated because the lowerholding portion 36 is opened upward. On the other hand, a place that theflexible flat cable 52 is held by the upper holding portion 38, adownward movement is not regulated because the upper holding portion 38is opened downward. That is, a turn of the flexible flat cable 52 in thecounterclockwise direction shown by an arrow mark R1 in the drawing isregulated, but a turn in the clockwise direction shown by an arrow markR2 in the drawing is not regulated. Accordingly, the rise of a portionof the flexible flat cable 52 ahead the place that is held by the upperholding portion 38 (at a side of connection to the control circuit 5)can be prevented.

FIG. 12 is an enlarged side view of the upper holding portion 38 andFIG. 13 is a cross-sectional view at a line of B-B′ shown in FIG. 12. Asshown in FIG. 13, the upper holding portion 38 is formed in a hook-likeshape that is opened downward, i.e., an inverted recess. That is, theupper holding portion 38 is constructed by a protruding portion 380 athat raises from the wall portion 37 of the image scanning unit 3 andprotruded toward the upstream of the sub scanning direction (Y2direction) from the wall portion 37, and a claw portion 380 b that isprovided to be continued to the protruding portion 380 a and in parallelwith the wall portion 37.

That is, since the flexible flat cable 52 is held by the upper holdingportion 38, the upward movement of the flexible flat cable 52 isregulated by the protruding portion 380 a and release of the flexibleflat cable 52 from the protruding portion 380 a is prevented by the clawportion 380 b. That is, a movement of the flexible flat cable 52 towardthe upstream side of the sub scanning direction (Y2 direction) isregulated by the claw portion 380 b.

Furthermore, an upper surface 38 a of an interior of the upper holdingportion 38 that forms such an inverted recess (a lower surface of theprotruding portion 380 a) is inclined to be lowered as going forward(see FIG. 12). The upper surface 38 a is inclined downward as far fromthe connection end portion 52 a of the flexible flat cable 52.

As shown in FIG. 11, the turn of the flexible flat cable 52 in adirection of the arrow mark R2 is not regulated, and the upper surface38 a of the inside of the upper holding portion 38 is inclined asdescribe above (see FIG. 12), and accordingly, the flexible flat cable52 is easy to take a slightly inclined state so as to become lower asgoing forward. Therefore, due to this, the portion ahead of the placethat the flexible flat cable 52 is held by the upper holding portion 38(a connecting side to the control circuit 5) is prevented from rising.

Furthermore, since the holding portion 351 is provided in close to therear of the lower holding portion 36 (adjacent to the lower holdingportion 36) and the connection end portion 52 a is held by the holdingportion 351 as shown in FIG. 11, the rise of the connection end portion52 a is prevented and the rise of the flexible flat cable 52 at thelower holding portion 36 close to the connection end portion 52 a isalso prevented. Therefore, the flexible flat cable 52 is prevented fromturning in the R2 direction more than necessary and thus the contactwith the platen glass 2, the involution in the image scanning unit 3,etc. of the flexible flat cable 52 are prevented.

According to the first embodiment, the flexible flat cable 52 is held inthree places of the holding portion 351, the lower holding portion 36and the upper holding portion 38, and therefore, it is possible toregulate the movements of the flexible flat cable 52 upward anddownward. Therefore, it is possible to prevent the flexible flat cable52 from being brought into contact with the platen glass 2 and the innerbottom surface of the lower housing 6 b. Accordingly, it is possible toprevent the platen glass 2 from being damaged and the flexible flatcable 52 from being broken before happen. In addition, the structurethat the flexible flat cable 52 is held at three places of the holdingportion 351, the lower holding portion 36 and the upper holding portion38 is described in the above-described first embodiment; however, notlimited to such structure. Structure that the flexible flat cable 52 isheld at two places of the lower holding portion 36 and the upper holdingportion 38 by omitting the holding portion 351 may be adopted, orstructure that the flexible flat cable 52 is held at only one place ofthe upper holding portion 38 by omitting the holding portion 351 and thelower holding portion 36 may be adopted.

Furthermore, in the above-described first embodiment, the upper holdingportion 38 is formed in the inverted recess shape, but not limited tosuch the structure. The upper holding portion 38 has only to regulatethe movement of the flexible flat cable 52 upward and to prevent such aregulated state from being canceled. Therefore, as shown in FIG. 15(A),the protruding portion 380 a is inclined downward as going to theupstream side of the sub scanning direction, and then, the claw portion380 b may be omitted. Furthermore, as shown in FIG. 15(B), by extendingthe protruding portion 380 a to the upstream side of the sub scanningdirection (Y2 direction), the claw portion 380 b may be omitted. Inthese cases, by means of the protruding portion 380 a, the movement ofthe flexible flat cable 52 upward is regulated and the regulated stateis prevented from being canceled.

Furthermore, in the above-described first embodiment, the controlcircuit 5 is provided inside the housing of the image reading apparatus10 and the flexible flat cable 52 is connected to the control circuit 5,but the control circuit 5 may be provided at a side of the main body(image forming portion) 20 of the image forming apparatus 1. In such acase, the control circuit 5 may be included in a control circuit that isprovided in the main body (image forming portion) 20 of the imageforming apparatus 1. In addition, in the above-described firstembodiment, the structure that the lower holding portion 36 is providedat a position apart from the rear end of the connector 34 a by adistance approximately 2 times the width of the flexible flat cable 52,but not limited to such the structure. It should be noted, however, inview of a point that the rise of the flexible flat cable 52 is to beprevented and the wiring operation is to be made easy, it is preferablethat the lower holding portion 36 is provided at a position apart fromthe rear end of the connector 34 a by a distance approximately 1.5 timesto 2.5 times the width of the flexible flat cable 52.

Furthermore, in the above-described first embodiment, the structure thatthe upper holding portion 38 is provided at a position apart from therear end of the connector 34 a by a distance approximately 2.5 times thewidth of the flexible flat cable 52, but not limited to such thestructure. It should be noted, however, in view of a point that the riseof the flexible flat cable 52 is to be prevented and the wiringoperation is to be made easy, it is preferable that the upper holdingportion 38 is provided at a position apart from the rear end of theconnector 34 a by a distance approximately 2 times to 3 times the widthof the flexible flat cable 52.

In addition, in the above-described first embodiment, the structure thatthe drive signal transmitting cable 51 and the flexible flat cable 52are connected to the control circuit 5 having the driving circuit fordriving the stepping motor 41, the signal processing circuit forprocessing the image signal that is output from the image scanning unit3 and the power source circuit, but not limited to such the structure.

Structure that the drive signal transmitting cable 51 and the flexibleflat cable 52 are not directly connected to the control circuit 5, thedrive signal transmitting cable 51 and the flexible flat cable 52 areconnected to a relay circuit board that relays the connection to thecontrol circuit 5. In such a case, a circuit board that is provided withthe control circuit 5 can be provided on the main body 20, and the relaycircuit board and the control circuit 5 are connected to each other by acable or the like, and the image signal that is received by the relaycircuit is transmitted to the control circuit 5, and the drive signal issupplied to the stepping motor 41, etc. via the relay circuit board fromthe control circuit 5.

Furthermore, in the above-described first embodiment, the structure thatthe image forming apparatus 1 that comprises the image reading apparatus10 and the main body 20 is described, but not limited to such thestructure. It is possible to provide an image reading apparatus thatdoes not have structure that a read image is formed on a recordingmedium such as a scanner apparatus of a flat-bet type, for example.

Second Embodiment

An image forming apparatus 1 according to the second embodiment isidentical to the first embodiment except for different structure of animage reading apparatus, and therefore, only different points aredescribed and a duplicate description will be omitted here.

In addition, the second embodiment will be described by using the samereference numerals or symbols for the same components as those of thefirst embodiment.

FIG. 16 shows an image reading apparatus 400 according to the secondembodiment, which comprises an automatic feeding portion 402 that hasstructure that originals can be sequentially supplied and a readingportion 404 that reads an original. In addition, in FIG. 16, as for theautomatic feeding portion 402, a side surface is shown and as for thereading portion 404, a state seen through the side surface.

As shown in FIG. 16, the image reading apparatus 400 comprises an imagescanning unit 410 that is provided with a light source. The imagescanning unit 410 comprises a pair of light source portions 412 and afirst mirror 414 that is irradiated by the pair of light source portions412 and changes an optical path of a reflected light that is reflectedby the original.

The reflected light that the optical path is changed is introduced intoan image signal producing portion 420 that comprises a second mirror422, a third mirror 423, a lens 424 and an imaging device 425.

Therefore, the reflected light that is introduced into the image signalproducing portion 420 is changed its optical path by the second mirror422 and the third mirror 423, and the reflected light that the opticalpath is changed is focused by the lens 424 to be input to the imagingdevice 425. The imaging device 425 such as a CCD performs aphotoelectric conversion of the reflected light to produce an electricsignal (image signal). Although not shown, a produced image signal isapplied to the control circuit 5 by using a signal cable.

FIG. 17 is a perspective view of the image reading portion 404 accordingto the second embodiment viewed from oblique above. The image readingportion 404 comprises the above-described image scanning unit 410 andthe image signal producing portion 412 as shown in FIG. 17. Although notshown, the image reading portion 404 is provided with a mechanism formoving (scanning) the image scanning unit 410 and the image signalproducing portion 420 in the sub scanning direction Y along thetransparent plate.

As similar to the first embodiment, the image scanning unit 410 isprovided with the holding portion 351, the lower holding portion 36 andthe upper holding portion 38 at the upper stream side of the subscanning direction (Y2 direction) and nearer the rear side of the mainscanning direction X (X2 direction). Accordingly, the flexible flatcable 52 is held by the holding portion 351, the lower holding portion36 and the upper holding portion 38 at the connection end portion 52 aand thus movements downward and upward can be regulated.

In addition, the image scanning unit 410 in the second embodiment isapplied with a control signal for scanning the original from the controlcircuit 5. The control signal is input through the flexible flat cable52. In addition, a part of the flexible flat cable 52 and the controlcircuit 5 are omitted in FIG. 17, but these portions are identical to acase shown in the first embodiment.

According to the second embodiment, as for the image scanning unit 410that is not provided with a mechanism for producing an image signal, byproviding the holding portion 351, the lower holding portion 36 and theupper holding portion 38, it is possible to prevent the platen glassfrom being damaged and the flexible flat cable 52 from being brokenbefore happen.

Third Embodiment

An image forming apparatus 1 according to the third embodiment isidentical to the first embodiment except for different positions thatthe holding portion 351, the lower holding portion 36 and the upperholding portion 38 are provided, and therefore, only different portionswill be described and a duplicate description will be omitted here.

As shown in FIG. 18, in the third embodiment, the holding portion 351,the lower holding portion 36 and the upper holding portion 38 areprovided at the downstream side of the sub scanning direction (Y1direction) in the image scanning unit 3. In such a case, the connector34 a is also provided at the downstream side of the sub scanningdirection (Y1 direction) in the image scanning unit 3.

In addition, as shown in FIG. 18, in the third embodiment, a hiatusportion is provided on the wall portion 62 at more upstream side of thesub scanning direction (Y2 direction) than the first embodiment, and theflexible flat cable 52 is brought into the area 7 b passing through thehiatus portion.

Therefore, in the third embodiment, the flexible flat cable 52 isextended toward the downstream side of the sub scanning direction aheadof the place that the flexible flat cable 52 is held by the upperholding portion 38. A further ahead portion thereof is turned downhorizontally in a U-letter shape, and turned forward the image scanningunit 3 through outside the holding portion 351, and is extended to theupstream side of the sub scanning direction along the wall portion 62.As described above, the hiatus portion is provided at the upstream sideof the sub scanning direction (Y2 direction) from a middle portion ofthe wall portion 62, and the flexible flat cable 52 is brought into, viathe hiatus portion, the area 7 b that is the rear side of the wallportion 62 and the control circuit 5 is arranged therein. Inside thearea 7 b, the flexible flat cable 52 is twisted horizontally from astate that the flexible flat cable 52 is raised vertically, andconnected to the control circuit 5 more ahead.

By adopting such structure, the flexible flat cable 52 can be also heldby the holding portion 351, the lower holding portion 36 and the upperholding portion 38 at the connection end portion 52 a, and movementsdownward and upward can be regulated.

In the third embodiment, it is also possible to prevent the platen glass2 from being damaged and the flexible flat cable 52 from being brokenbefore happen.

In addition, since the holding portion 351, the lower holding portion 36and the upper holding portion 38 are provided at the downstream side ofthe sub scanning direction (Y1 direction) in the third embodiment, it isnot necessary to provide the area 7 d.

Furthermore, it is also possible to provide the holding portion 351, thelower holding portion 36 and the upper holding portion 38 at thedownstream side of the sub scanning direction (Y1 direction) in theimage reading apparatus 400 according to the second embodiment.

Although the present invention has been described and illustrated indetail, it is clearly understood that the same is by way of illustrationand example only and is not to be taken by way of limitation, the spiritand scope of the present invention being limited only by the terms ofthe appended claims.

What is claimed is:
 1. An image reading apparatus, comprising: aflat-plate-like transparent plate on which an original is put; ascanning portion that is provided beneath the transparent plate and thatscans the original being put on the transparent plate with movementthereof, the scanning portion reading an image from the original tooutput an image signal; and a signal cable that is belt-like and has oneend connected to a connection portion of the scanning portion andanother end that outputs at least the image signal being output from thescanning portion, wherein the signal cable is arranged such that a widthdirection of the signal cable intersects with a plane of the transparentplate in at least a part of a length direction of the signal cable, andthe scanning portion comprises an upper regulating portion thatregulates an upward movement of the signal cable.
 2. The image readingapparatus according to claim 1, wherein the upper regulating portion hasa slant surface that is inclined downward as far from the one end of thesignal cable.
 3. The image reading apparatus according to claim 1,wherein the width direction of the one end of the signal cable issubstantially parallel to the transparent plate, and the scanningportion comprises a shape holding portion that holds the signal cablesuch that the width direction of the signal cable that is extended fromthe connection portion is changed toward an orientation where the widthdirection of the signal cable is substantially perpendicular to thetransparent plate.
 4. The image reading apparatus according to claim 1,wherein the connection portion is arranged closer to one end side of thescanning portion in comparison to the upper regulating portion in thelongitudinal direction of the scanning portion when viewing from anupstream side of a moving direction of the scanning portion in scanningthe original.
 5. The image reading apparatus according to claim 1,wherein the one end of the signal cable is arranged such that the widthdirection is substantially parallel to the transparent plate where itconnects to the connection portion of the scanning portion, and whereinthe signal cable extends along a wall portion that extends in a movingdirection of the scanning portion in a state that a width direction ofthe signal cable is substantially perpendicular to the transparentplate.
 6. The image reading apparatus according to claim 1, wherein theupper regulating portion regulates a movement of the signal cable withina section where the signal cable is changed from the horizontal state tothe vertical state.
 7. The image reading apparatus according to claim 1,wherein the upper regulating portion includes a second protrudingportion that is extended toward an upstream side of a moving directionof the scanning portion in scanning the original to regulate themovement of the signal cable in an upward direction, and a thirdprotruding portion that is extended from an end portion of the secondprotruding portion downwardly to regulate the movement of the signalcable toward the upstream side in scanning the original.
 8. The imagereading apparatus according to claim 1, wherein said another end of thesignal cable is connected to a circuitry portion that receives at leastthe image signal being output from the scanning portion, and the one endof the signal cable is connected to the connection portion of thescanning portion nearer the circuitry portion in a longitudinaldirection of the scanning portion.
 9. The image reading apparatusaccording to claim 1, wherein the one end of the signal cable isconnected to the connection portion of the scanning portion in anupstream side of a moving direction of the scanning portion in scanningthe original, and the upper regulating portion is provided in anupstream side of a moving direction of the scanning portion in scanningthe original.
 10. The image reading apparatus according to claim 1,wherein the upper regulating portion is formed integrally with thescanning portion.
 11. The image reading apparatus according to claim 1,wherein the upper regulating portion is formed in a lower side than anupper surface of the scanning portion.
 12. An image forming apparatus,comprising: the image reading apparatus of the claim 1; and an imageforming portion where an image that is read by the image readingapparatus is formed on a recording medium.